Apparatus for bundling by strapping PET bottles or similar containers

ABSTRACT

An apparatus for strapping bundles of PET bottles, cans, jars or similar containers arranged on four operating levels includes two horizontal strapping machines.

DESCRIPTION

In the current state of art, containers such as PET bottles for beverages and, moreover, also other equivalent containers such as cans and/or jars, are assembled in groups or bundles of four or six or more elements mainly by means of sheets of heat-shrinking plastic polymers.

The present invention, instead, relates to another method of fast assembly and therefore a new type of apparatus, safe and economical by using of tape-like constraints called straps usable with appropriate and specific measures using traditional strapping machines. Said machines have already existed for a long time for the general packaging of packages, boxes or various containers but have not yet been used industrially for the assembly of PET bottles or similar containers.

Only machines suitable for this purpose are known, for example the machine described in document WO2013018047.

In this machine it is possible to produce packs of containers, so called bundles wherein the containers are held together by at least two straps oriented to subtend a plane perpendicular to the axes of the themselves containers. Furthermore, the machine described can only produce bundles wherein the containers are arranged in such a way that on each side of the bundle the containers are all tangent to a plane which is parallel to the axis of the containers themselves. Therefore, said machine according to the state of art does not allow to produce bundles of containers arranged in quinconce, i.e. the shell surfaces of the containers arranged along the perimeter sides of the bundle are not all tangent with a plane parallel to the axes of said containers and defining the side of the bundle itself.

The purpose of the present invention is to provide an apparatus for the production of bundles consisting of groups of containers which are held together by at least one, preferably two or more straps and which allows high productivity and easy adaptation to the production of bundles in which the groups of containers comprise different relative arrangements of the containers themselves and in a quinconce or any arrangement of the said containers wherein along the sides of the bundle not all containers are tangent to a plane that defines the said side of the bundles.

The apparatus, object of the present invention, relates to an operating unit capable of carrying out a rapid assembly, i.e. a safe and simple bundle comprising at least one, preferably two straps: arranged on planes parallel to each other and perpendicular to the axes of the containers of the group.

A possible embodiment may additionally provide at least a third strap oriented perpendicular to the two said straps, i.e. extending in a plane parallel to the axes of the containers and preferably passing through the gravity centre of the containers group bound together to form the package or bundle.

The apparatus of the present invention is provided to simplify and minimise the shrinkwrapping time, thus ensuring a reduced operating cost in conjunction with constant and reliable working and to ensure a simple and rapid adaptability of the apparatus to a multiple of pack configuration which differ in that they have containers arranged according to pattern wherein at least on one side of the pack or bundle not all containers are tangent to a plane coinciding and/or extending along said side.

The apparatus according to the present invention is designed for bundling, by strapping, of containers, that is, for binding a predetermined number of containers arranged relatively to each other according to a predetermined order so as to form a compact pack or bundle that act as a single package.

The containers can be of any type, for example plastic bottles, such as PET bottles, or cans or cardboard containers or glass containers such as jars, bottles, or other types of similar containers.

The invention relates to a machine of the type essentially comprising a conveyor belt feeding a series of containers to a forming station, wherein said containers are formed in a sequence of ordered groups of containers comprising a predetermined number of containers with a predetermined relative arrangement of said containers, which conveyor and which forming station are provided at a first intermediate level, by a conveyor for transferring a series of said ordered groups of containers to a strapping station, which strapping station is foreseen at a second intermediate level, and by a conveyor for unloading said series of ordered groups foreseen downstream of said strapping station and at a level which is lower than said second intermediate level.

According to a first embodiment of the invention, to allow an easy and easily variable arrangement of the containers according to a predetermined order, the present invention provides in combination further features that

the forming station provides stationary sequencers of the containers on a predetermined number of parallel rows of containers oriented in the forward direction of said feeding conveyor, while an end stop wall of the containers is provided at the front regarding to the forward direction of said conveyor,

the shape of said wall corresponding to a predetermined relative arrangement of the containers on the front face of the group of containers,

the transfer conveyor being provided at a higher level than said forming station of the containers group, said level being spaced from the level of the forming station by an extent at least corresponding to the height of the containers or greater,

in the forming station being provided a container lifting unit from the intermediate level of said forming station to the upper level of the transfer conveyor,

while the transfer conveyor unloads in succession the formed groups of containers in a descent station wherein the containers are transferred by a vertical translation, by gravity in the strapping station at the said second intermediate level and from said second intermediate level the said bottles are transferred by a vertically movable support to the lower level of the unloading conveyor.

The apparatus described basically works on four levels or planes, which are:

A) First intermediate level of container feeding at the forming station of the ordered groups of containers and forming said groups. B) upper level of transfer from the forming station to the descent station by a transfer conveyor along a predetermined path; C) Second intermediate level of strapping for application of two simultaneous horizontal strapping that bind together the containers. Said strapping is performed by two strapping machines whose strapping planes are superimpose vertically on each other and are spaced from each other in the axial direction of the containers.

The distance between the two straps can profitably correspond to the distance of the annular grooves on the shell surfaces of the containers and inside the straps, i.e. the binding tapes, are housed.

D) lower unloading level wherein the containers group tied together in the strapping station are transferred in order to be unloaded from the machine and sent for other processes, such as palletizing.

As will become clearer below, the forming station provides that the containers are not brought at least on some sides of the same in contact with the adjacent containers, but said containers are kept spaced apart at a predetermined distance, at least in correspondence with some sides facing towards one or more of the adjacent containers and that the group of containers generated in the forming station with this spaced configuration of the containers is thus transferred to the transfer conveyor.

According to an embodiment, still in the forming station or at the entry to the transfer conveyor, it is possible to provide a dispensing unit for an adhesive substance and/or a substance that increases the friction between the mutual contact surfaces of the containers, which substance can be applied on at least some areas of the surfaces of mutual contact between adjacent containers and which surfaces are provided on the still spaced sides of the adjacent containers.

In this case, there is a clear feature of the transfer path of the series of containers group from the groups forming station to the strapping station or descent towards the strapping station is evident.

In fact, during this path it is possible to provide compacting units of the containers into contact each other, for example lateral pressors and/or in the forward direction that bring the containers together into mutual contact and bringing the areas on which the substance has been deposited to adhere adhesive or the adhesion or friction increase coating.

Furthermore, the length of the transfer path is set in a way that the transfer time of the containers allows the substance applied to the adhesion areas to dry sufficiently so that the action of this substance is not compromised by the further processing steps for the generation of the package or the bundle.

Further features of the invention or improvements or variations are the subject of the dependent claims.

The features of the invention and the advantages derived from it will be better described by the following non-limiting description of an embodiment illustrated in the attached figures, wherein:

FIGS. 1 and 2 show two perspective views according to two different directions of a simplified embodiment of the apparatus according to the present invention.

FIG. 3 shows a side view of the apparatus according to the previous figures.

FIGS. 4 and 5 show two section views of the apparatus according to the figures present according to a vertical section plane, or parallel to the axes of the bottles and oriented in the forward direction on the conveyors.

FIG. 6 shows a view wherein the transfer conveyor has been partially omitted.

The apparatus for production of containers packs, so-called bundles, is illustrated in a non-limiting way referring to bottles, to plastic bottles, such as PET or other materials. In fact, as is immediately clear, the same apparatus can be used to produce packs of other types of containers, such as glass bottles, cans, jars, and cardboard containers or similar.

The apparatus has a feed conveyor 1 wherein rows of containers 2 are fed to a forming station S1 of ordered groups of containers. Each group comprises a predetermined number of containers which are arranged according to a predetermined pattern.

In particular, the illustrated apparatus allows to create groups of containers which are arranged relatively to each other in a way that the group has at least one side part of the containers which are arranged tangent to a plane which defines said side and part of said containers which is spaced from said plane.

In the embodiment for simplicity, a variant is shown in which the containers of the group are arranged in two rows and in quinconce in each of said rows.

The number of containers for each group may vary depending on the case and/or also the relative arrangement of the same within the group.

In the forming station S1, the containers 2 are arranged on a plurality of parallel rows oriented parallel to each other in the forward direction of the feed conveyor 1.

According to an embodiment, this is possible thanks by deviation and guide walls 3 which are oriented parallel to the axes of the containers and which extend for a certain length in the forward direction of the containers 2.

The said deviation and guide walls 3 have a certain thickness which arranges the containers 2 on several rows at a lateral distance from each other, or crosswise to the forward direction.

The forming station S1 has an end-stop advancement wall 4 for advancing the containers which has a template, and which has a three-dimensional shape. The shape of said end-stop wall, or the cross-section shape along a horizontal plane of said end-stop wall 4 defines the relative position of the container in front position of each row of containers 2 in the forming station S 1. In this case the said end-stop wall 4 is made in such a way as to position the containers 2 in quinconce, so that the said end-stop wall 4 has flat end stop faces and coincide with two different vertical planes oriented crosswise to the forward direction and spaced from each other for a measure substantially corresponding to a radius or to half the size of the container in the forward direction.

The said wall 4 is formed by two alternating series of stop surfaces 104, 204 which are each coincident with a row of containers 2 and which are coincident respectively with one of said two vertical planes and cross-sectional to the forward direction.

The group of containers 1 formed in the forming station S1 has several rows of containers 2 side by side and spaced apart in a predetermined size and which rows are arranged staggered from each other in the forward direction of the containers to such an extent that the containers are arranged in quinconce.

In the illustrated embodiment, the group of containers comprises only two rows of containers placed side by side in a cross direction to the forward direction, while it has five rows of containers parallel to each other and spaced apart in a cross direction to the forward direction.

A lifting assembly (not shown in detail) can be made in various ways known to the state of art and for example comprises of a group of pushing rods, each comes into contact with the bottom of a container or with a plate that comes into contact with part of the bottom of at least two or more containers and which pushing rods can be moved vertically in both directions raises the group of containers 2 formed in station S1 at a first intermediate level LV1 at an upper level and in the inlet end of a transfer conveyor 5.

A shaped wall 6 corresponding to the surfaces of the containers of the group formed in the station S1 is provided on the side of the group which is backward to the forward direction of the containers on the conveyor 1.

In the illustrated embodiment wherein the group of containers has five rows comprising two containers 2 for each row, said rear wall 6 is shaped correspondingly to the end-stop wall 4 and also has the function of template.

The said wall 4 can be movable from the forming station S1 to the entrance into the transfer conveyor, or it can be provided only at the entrance of the transfer conveyor 5.

Said rear wall 6 moves together with the containers 2 of the group and accompanies, pushing the containers of the group towards a descent station S2 at the opposite end of a transfer path PT.

According to an embodiment, a possible transfer conveyor comprises a container sliding surface which can be stationary or consisting of a movable conveyor belt that is displaceable either idle or motorized and in combination a multiple of driving pressors members 105 in the form of crosspieces movable by an end belts or chains, which belts or chains 205 move along closed paths and are driven around pulleys or gears 405 at least some of which are rotationally driven by motors (not shown).

Each crosswise driving pressor 105 carries a shaped wall with the function of template 6 and cooperates with a group of containers, the said pressors 105 being arranged at distances from each other as to allow each group formed between two said pressors 105 to be housed, thus forming a series of groups of containers 2.

It should be noted that in FIGS. 1 and 2 the sliding surface of the containers 2 in the transfer conveyor 5 is not visible, while FIGS. 3 to 6 show it and it is indicated by the number 305.

During the movement on the transfer path PT, the containers of each group are subjected to a compacting operation, that is to approach each other to be brought into mutual contact of each container with the adjacent containers.

In the example illustrated, wherein the containers are arranged in several rows spaced apart in the crosswise of forward direction, the compaction takes place through two lateral pressors aligned and/or coincident with each other in a cross forward direction of the groups of containers and each arranged on a longitudinal side of the transfer conveyor 5 and can be moved towards and relative to each other. The said two lateral pressors are not illustrated in detail, but for example they can be constituted by a pair of opposing pressure plates oriented vertically and parallel to the forward direction and which are moved parallel to themselves by at least a linear actuator.

According to another feature, the said compactors, i.e. the lateral pressors opposite each other, are provided in a point of the transfer path PT which is downstream of an intermediate station for applying an adhesive or a coating to increase the friction between the containers of a group.

This station is also not illustrated in detail and can be realized in any way by a skilled person using his basic knowledge.

In particular, said station may comprise at least one nozzle or a multiples of spray nozzles which can be moved along the group of containers or arranged in a predetermined relative position with reference to at least some of the containers, in order to project a predetermined quantity of adhesive, paint or other coating substance on at least some areas of the surface of the containers 2, in correspondence with said surfaces of adjacent containers come into contact with each other upon lateral compaction of the group of containers as described above.

It is possible to provide other methods of application such as the application of double-sided adhesive tapes or similar.

The position of the station for applying the adhesive and/or substance to increase the friction between the surfaces of two adjacent containers is such that the remaining length of the transfer path PT and the descent into the strapping station SR provided at a second intermediate level LV3 is enough to allow a substantial drying of the adhesive, paint or other substance to an extent that does not compromise the effect of retaining the individual containers fixed in a releasable way to each other even during further movements of the group of containers in the plant for the subsequent phases.

As shown in FIGS. 4 and following, an embodiment provides that the wall with the function of a rear template 6 is provided only at the entrance of the transfer conveyor 5, while the pressors rods push each group by acting directly on the containers 2 that protrude from the rear.

On leaving transfer conveyor 5, the individual groups of containers are placed in a vertical descent station towards a strapping station SR.

The strapping station SR is provided at a lower level than the transfer conveyor and at the intermediate level of the forming station of the groups of containers S1.

The difference in height between each level is substantially corresponding to the height of the containers or a multiple of thereof.

Considering that as shown in the figures, the distance between the intermediate level LV1 of the forming station S1 and the intermediate level LV2 of the strapping station SR is equal to the height of the containers and the distance between the intermediate level LV1 of the forming station S1 and the LVS level of the transfer conveyor 5 is also equal to height of the containers 2, the strapping station SR is provided at a level LS2 which is lower than the upper level LVS of the output of the transfer conveyor 5 which is substantially equal twice the height of the containers 2.

As is clear , in the descent station SD, the containers 2 of the individual groups which are not yet strapped together are supported in the strapping station SR by lower, removable support stops, indicated schematically in FIGS. 4 and 5 with 7, while after the application of the two straps along the two horizontal planes and perpendicular to the axis of the containers by means of the strapping machines R1 and R2, the group of linked containers 2 is unloaded from the strapping machine by a lifting/lowering conveyor 8 which feeds each group at the entrance of an unloading conveyor 9.

The lowering conveyor is motorized with regards to the vertical movement of lifting and lowering between the intermediate level LV2 of the strapping station SR and the lower level LVINF of an unloading conveyor 9.

A particular embodiment which is the one illustrated provides that both the lowering conveyor 8 and the unloading conveyor 9 are in the form of conveyor belts.

However, any type of conveyor can be provided.

Similarly, to the intermediate and upper levels, the lower level LVINF of the unloading conveyor 9 is also provided at a distance essentially corresponding to the height of the containers or possibly even slightly higher than the said height of the containers.

As it's clear, the group of containers 2 exiting the transfer conveyor 5 and entering the lowering station SD is held at the upper level LVS by removable support members shown schematically and indicated with 10 in FIGS. 4 and 5 . Descent station that ends in the strapping station SR has a descent channel whose length is basically equal to the height of the containers or to a multiple of said height, so that between the group of containers in the strapping station SR and the group of outgoing containers one or more vertically aligned groups are provided from the transfer conveyor and at the inlet to the descent station according to whether the channel of the descent station is long to an extent equal to a single height of the containers 2 or a multiple of said height.

Furthermore, the descent takes place by gravity since the descent station has no vertical transfer members for the containers, and since the containers of the group or groups of containers are interposed between the group in the strapping station SR and the group entering the descent station SD supported respectively by the containers of the underlying group, that is of the group of containers in the strapping station and/or in the group of containers of the succession of groups 2″ present in the descent channel when this has a length equal to a multiple of the heights of the containers. The last group 2′ at the upper end of the descent channel in turn supports the containers of the group leaving the transfer conveyor, when the removable support members 10 are moved to an inactive position and the containers of said group are free to move downwards by gravity.

As it appears clear from the previous description, the adaptation of the apparatus to forming of packs or bundles of containers with a predetermined order and number of containers takes place simply by replacing the walls 4 and 6. In fact, the relative arrangement of the containers on the individual rows is determined by the shape of the said walls.

Furthermore, by providing for a forming unit which comprises the deviation and guide walls as separate parts or as parts joined together in a unit, it is possible to modify the configuration of the group of containers also as regards the number of rows and not only the arrangement of the containers within the said rows.

It is clear that the conveyors, the moving parts of the containers and the strapping machines are independent of the configuration of the container groups as regards the number and arrangement of the same within a certain limit of the said number and the order of positioning of the containers in the group. This makes the apparatus extremely flexible to be quickly adapted and with low costs to different configurations of packs or bundles of containers.

The possibility of applying on at least part of the reciprocal contact areas of the containers an adhesive substance and/or a coating that also has an adhesive function or an increase in friction allows to create groups of containers wherein the central containers are relatively distant from the holds, and these containers can move axially with respect to the others even slipping out of the group and therefore effectively dissolving the bond that binds the containers together.

This effect depends both on the material of which the containers are made and on the shape of the containers themselves and the possibility of axial offset and/or extraction increases with low-friction metal materials and/or with smooth and not three-dimensionally shaped surfaces of the containers.

This measure makes the system even more flexible with regard to the possible different configurations of the packs or bundles.

LEGEND

feed conveyor 1 containers 2 forming station of ordered groups of containers S1 longitudinal deflection and guide walls 3 advancement end-stop wall with 4 positioning template function limit stop surfaces 104, 204 first intermediate level LV1 transfer conveyor 5 rear shaped positioning wall 6 descent station SD transfer course PT transverse drag pusher 105  belts or chains 205  sliding plane 305  pulleys or gears 405  strapping station SR second intermediate level LV2 upper level LVS removable lower support 7 strapping machines R1 and R2 lift/lower conveyor 8 unloading conveyor 9 lower level LVINF removable support members 10  the last group 2′ at the upper end of the descent channel succession of 2″ groups present in the descent channel between the upper LVS level and the second intermediate level LV2 

The invention claimed is:
 1. An apparatus for bundling, by strapping, PET bottles or other containers comprising: a feed conveyor belt for feeding a series of containers to a forming station of ordered groups of containers, each ordered group comprising a predetermined number of the containers with an arrangement relative to the feed conveyor, the forming station being provided at a first intermediate level; and a transfer conveyor for transferring a succession of said ordered groups to a strapping station provided at a second intermediate level, a discharge conveyor for unloading said ordered groups in succession being provided at a lower level than said second intermediate level, wherein the forming station provides stationary sequencers of the containers on a predetermined number of rows of the containers parallel and oriented in a forward direction of said feed conveyor, an end-stop wall for the containers being provided in a front position with regard to a direction of movement of said feed conveyor, wherein a shape of said end-stop wall corresponds to a predetermined relative arrangement of the containers on a front face of the ordered groups of the containers, and wherein the transfer conveyor is provided at a higher level than said forming station, said higher level being spaced from a level of the forming station to an extent at least corresponding to a height of the containers or greater; and a lifting assembly provided in the forming station, the lifting assembly being for the containers of a group formed of the containers from the first intermediate level of said forming station to an upper level of the transfer conveyor, wherein the transfer conveyor unloads in succession the ordered groups of the containers in a descent station in which the containers are transferred by vertical translation, by gravity, in the strapping station to the second intermediate level, and from the second intermediate level the containers are transferred by a vertically movable support to the lower level of the discharge conveyor.
 2. The apparatus according to claim 1, wherein the second intermediate level is spaced from said first intermediate level by a distance equal to a height of the containers, and wherein a intermediate passage station is provided between the descent station leaving the transfer conveyor and an intermediate passage of the strapping station, which is at the first intermediate level of the forming station, and in which a group of the containers is supported by the containers of the group of the containers in the strapping station and the containers of the group in said intermediate passage station support the containers of the group of the containers in the descent station.
 3. The apparatus according to claim 1, wherein the containers of the group formed in the forming station are spaced apart from rows of the containers oriented in a forward direction of the forming station, and wherein the containers of each group are compacted together in a cross direction to the forward direction by a container compactor having opposing lateral pressors provided along a path of the transfer conveyor.
 4. The apparatus according to claim 3, wherein, upstream of the container compactor of each group of the containers, there is a station for dispensing/spraying an adhesive substance on at least one or more areas of mutual contact of the containers of each group in a compacted together condition.
 5. The apparatus according to claim 1, wherein at least two strapping machines are provided, which are spaced vertically from each other or in a containers axis direction in order to arrange corresponding straps in points axially spaced from each other.
 6. The apparatus according to claim 1, wherein, in the forming station and/or at an entrance to the transfer conveyor, there is provided a shaped forming wall of a rear side of the group of the containers corresponding to a predetermined order and a predetermined position relative to the containers of the group in correspondence with the said rear side.
 7. The apparatus according to claim 1, wherein the stationary sequencers of the containers on several adjacent and parallel rows of the containers provided in the forming station are composed of a plurality of dividing walls of the rows, said walls being oriented in a forward direction of the containers and parallel to vertical axes of the containers, and wherein the walls have a predetermined thickness for a lateral spacing to a predetermined extent of the rows of the containers between the walls.
 8. The apparatus according to claim 1, wherein at least one additional vertically oriented strapping machine is provided for application of a vertical strap, oriented in a plane parallel to the containers axes.
 9. The apparatus according to claim 1, wherein the group of the containers in the strapping station is supported by a conveyor belt which can be raised to a level of said strapping station and lowered to a lower level of the discharge conveyor, said lower level being lower than the level of the strapping station to an extent corresponding to the height of the containers, and wherein, at the level of the strapping station, a removable support of the group of the containers is provided.
 10. The apparatus according to claim 4, wherein said adhesive substance is a glue, a paint, a coating, an external finishing substance of the containers, or a combination thereof, and wherein the adhesive substance is applied to at least some areas or on an entire surface of the containers.
 11. The apparatus according to claim 1, wherein an advancement end-stop switch wall operating as a template, end-stop surfaces, and a rear shaped positioning wall are constituted by independent shaped elements, axially actuated according to a motion of the containers that are incoming, by a mechanized or electrically operated system, so as to make a size of the group of the containers adjustable to a predetermined size before lifting. 